The present invention refers to a blood sampling device comprising a piston-cylinder arrangement as an intermediate storage for diluted blood, said piston-cylinder arrangement comprises a cylindrical housing cooperating with a through-flow channel and being closed by means of a rotating handle, and a piston moving within said cylindrical housing and connected to said handle. It is provided for, according to the present invention, that said piston (6) which is movable within said cylindrical housing (2) is actuated by means of an actuating means (12).
